HIV phenotypic resistance testing is the same as genotypic testing in that it tests the strain of HIV causing your infection for resistance to specific ARV, but it uses a different method. In the lab, a sample of the virus grown in culture is mixed with different concentrations of one or more drugs. If the virus is able to replicate in the presence of the drug, as compared to a known strain of virus (a reference virus), it is said to be resistant to that drug. This type of testing usually takes longer than genotypic resistance testing.
This article was last reviewed on November 30, 2012. | This article was last modified on November 30, 2012.
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